@@ -692,6 +692,44 @@ static bool fold_call(OptContext *ctx, TCGOp *op)
return true;
}
+static bool fold_mb(OptContext *ctx, TCGOp *op)
+{
+ /* Eliminate duplicate and redundant fence instructions. */
+ if (ctx->prev_mb) {
+ /*
+ * Merge two barriers of the same type into one,
+ * or a weaker barrier into a stronger one,
+ * or two weaker barriers into a stronger one.
+ * mb X; mb Y => mb X|Y
+ * mb; strl => mb; st
+ * ldaq; mb => ld; mb
+ * ldaq; strl => ld; mb; st
+ * Other combinations are also merged into a strong
+ * barrier. This is stricter than specified but for
+ * the purposes of TCG is better than not optimizing.
+ */
+ ctx->prev_mb->args[0] |= op->args[0];
+ tcg_op_remove(ctx->tcg, op);
+ } else {
+ ctx->prev_mb = op;
+ }
+ return true;
+}
+
+static bool fold_qemu_ld(OptContext *ctx, TCGOp *op)
+{
+ /* Opcodes that touch guest memory stop the mb optimization. */
+ ctx->prev_mb = NULL;
+ return false;
+}
+
+static bool fold_qemu_st(OptContext *ctx, TCGOp *op)
+{
+ /* Opcodes that touch guest memory stop the mb optimization. */
+ ctx->prev_mb = NULL;
+ return false;
+}
+
/* Propagate constants and copies, fold constant expressions. */
void tcg_optimize(TCGContext *s)
{
@@ -1599,6 +1637,19 @@ void tcg_optimize(TCGContext *s)
}
break;
+ case INDEX_op_mb:
+ done = fold_mb(&ctx, op);
+ break;
+ case INDEX_op_qemu_ld_i32:
+ case INDEX_op_qemu_ld_i64:
+ done = fold_qemu_ld(&ctx, op);
+ break;
+ case INDEX_op_qemu_st_i32:
+ case INDEX_op_qemu_st8_i32:
+ case INDEX_op_qemu_st_i64:
+ done = fold_qemu_st(&ctx, op);
+ break;
+
default:
break;
}
@@ -1606,43 +1657,5 @@ void tcg_optimize(TCGContext *s)
if (!done) {
finish_folding(&ctx, op);
}
-
- /* Eliminate duplicate and redundant fence instructions. */
- if (ctx.prev_mb) {
- switch (opc) {
- case INDEX_op_mb:
- /* Merge two barriers of the same type into one,
- * or a weaker barrier into a stronger one,
- * or two weaker barriers into a stronger one.
- * mb X; mb Y => mb X|Y
- * mb; strl => mb; st
- * ldaq; mb => ld; mb
- * ldaq; strl => ld; mb; st
- * Other combinations are also merged into a strong
- * barrier. This is stricter than specified but for
- * the purposes of TCG is better than not optimizing.
- */
- ctx.prev_mb->args[0] |= op->args[0];
- tcg_op_remove(s, op);
- break;
-
- default:
- /* Opcodes that end the block stop the optimization. */
- if ((def->flags & TCG_OPF_BB_END) == 0) {
- break;
- }
- /* fallthru */
- case INDEX_op_qemu_ld_i32:
- case INDEX_op_qemu_ld_i64:
- case INDEX_op_qemu_st_i32:
- case INDEX_op_qemu_st8_i32:
- case INDEX_op_qemu_st_i64:
- /* Opcodes that touch guest memory stop the optimization. */
- ctx.prev_mb = NULL;
- break;
- }
- } else if (opc == INDEX_op_mb) {
- ctx.prev_mb = op;
- }
}
}
This puts the separate mb optimization into the same framework as the others. While fold_qemu_{ld,st} are currently identical, that won't last as more code gets moved. Reviewed-by: Luis Pires <luis.pires@eldorado.org.br> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> --- tcg/optimize.c | 89 +++++++++++++++++++++++++++++--------------------- 1 file changed, 51 insertions(+), 38 deletions(-) -- 2.25.1